1. Technical Field
The present invention relates to a touch panel.
2. Description of the Related Art
With the development of computers using a digital technology, devices assisting computers have also been developed, and personal computers, portable transmitters and other personal information processors execute text and graphic processing using a variety of input devices such as a keyboard and a mouse.
While the rapid advancement of an information-oriented society has been widening the use of computers more and more, it is difficult to efficiently operate products using only a keyboard and mouse currently serving as an input device. Therefore, the need for a device that is simple, has minimum malfunction, and is capable of easily inputting information has increased.
In addition, current techniques for input devices have progressed toward techniques related to high reliability, durability, innovation, designing and processing beyond the level of satisfying general functions. To attain these objects, a touch panel has been developed as an input device capable of inputting information such as text, graphics, or the like.
The touch panel is mounted on the display surface of an image display device such as an electronic organizer, a flat panel display including a liquid crystal display device (LCD), a plasma display panel (PDP), an electroluminescence (El) element or the like, or a cathode ray tube (CRT), so that a user selects the desired information while viewing the image display device.
The touch panel is classified into a resistive type touch panel, a capacitive type touch panel, an electromagnetic type touch panel, a surface acoustic wave (SAW) type touch panel, and an infrared type touch panel. These various types of touch panels are adapted for electronic products in consideration of signal amplification problems, resolution difference, level of difficulty of designing and processing technologies, optical characteristics, electrical characteristics, mechanical characteristics, environment-resistant characteristics, input characteristics, durability, and economic efficiency. Currently, a capacitive type touch panel and a digital resistive type touch panel have been used in a wide range of fields.
An example of the capacitive type touch panel of the prior art is shown in Korean Laid-Open Publication No. 10-2011-0120157. In the touch panel disclosed in the above published patent, a plurality of electrodes are formed on a transparent substrate while having biaxial direction and crossing each other.
In addition, wirings are formed at one ends of the plurality of electrodes such that the wirings are electrically connected to the electrodes. A flexible printed circuit board (FPCB) is electrically connected to pad parts formed on terminals of the wirings.
In the touch panel having the above structure according to the prior art, the electrodes are disposed in an active area of a transparent substrate, which is exposed to the outside through the transparent substrate or a window glass, and the wirings are disposed in a non-active area of the transparent substrate, which is not exposed to the outside.
The reason that the wirings are disposed in the non-active area is that the wiring is generally linear, and thus, does not have pattern uniformity with the electrodes disposed in the active area of the transparent substrate.
In other words, in the case where the electrodes are formed in a mesh pattern, the linear wirings and electrodes have uniform patterns. Therefore, when the electrodes and wirings are formed together in the active area, visibility of the touch panel becomes defective.
Due to this, the touch panel of the prior art has wirings disposed in the non-active area of the transparent substrate, like the touch panel disclosed in the published patent above.
In the structure of the touch panel of the prior art, the wirings are disposed in the non-active area of the transparent substrate, and thus, the width of the non-active area of the touch panel is disadvantageously enlarged.
This disadvantage becomes an obstacle to miniaturize terminal devices employing the structure of the touch panel, or causes the active area of the transparent substrate, which is a touch area, to be reduced as compared with the same sized devices.